<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Document</title>

        <style>
            .top {
                position: relative;
                width: 200px;
                height: 100px;
                background-color: red;
            }

            .top>.in {
                width: 100px;
                height: 300px;
                background-color: yellow;
                position: absolute;
                z-index: 1000;
            }

            .bottom {
                position: relative;
                width: 200px;
                height: 100px;
                background-color: blue;
                z-index: 1;
            }
        
        </style>
    </head>
    <body>

        <div class="top">
            <div class="in"></div>
        </div>

        <div class="bottom">
            <div class="in"></div>
        </div>
        
    </body>
</html>